1H-1,2,3-triazol-5-ylthio ester of N-carbobenzyloxy-p-hydroxyphenylglycine

ABSTRACT

Novel thioesters effective as acylating agents for amines or hydrazines, especially effective as active esters in synthesis of cephalosporin compounds are disclosed. The novel thioester of the present invention can be prepared by reacting a thiol or a derivative thereof with an acetic acid derivative or a reactive derivative thereof. By reacting the thioester of the present invention with a 7-aminocephalosporin derivative or a salt thereof, cephalosporin derivatives or pharmacologically acceptable salts thereof which are excellent antibiotic substances having a high antimicrobial activity can be obtained in high yield very safely.

The present invention relates to novel thioesters effective as acylatingagents for amines and hydrazine especially effective as active esters insynthesis of cephalosporin compounds and a process for the preparationof the same, and a process for preparing cephalosporin derivatives andpharmacologically acceptable salts thereof by using the novelthioesters. More particularly the present invention is concerned with anovel thioester repreented by the following general formula (I):##STR1## wherein R₁ stands for a p-hydroxyphenyl group, atrifluoromethylthio group, a cyanomethylthio group, a chlorine atom or a2-thienyl group,

R₂ stands for hydrogen atom or an amino or protected amino group, and

R₃ stands for a 2-methyl-1,3,4-thiadiazol-5-ylthio group, a1H-1,2,3-triazol-5-ylthio group or a 1-methyl-1,2,3,4-tetrazol-5-ylthiogroup,

and a process for the preparation thereof which comprises reacting athiol represented by the following general formula (II) or itsderivative:

    H--R.sub.3                                                 (II)

wherein R₃ is as defined above,

with an acetic acid derivative represented by the following generalformula (III) or a reactive derivative thereof: ##STR2## wherein R₁ andR₂ are as defined above, and a process for the preparation of acephalosporin derivative represented by the following general formula(V) or pharmacologically acceptable salts thereof: ##STR3## wherein R₁,R₂, and R₃ are as defined above, and

R₄ stands for a hydrogen atom or a methoxy group,

which comprises reacting a 7-aminocephalosporanic acid derivativerepresented by the following general formula (IV) or a salts thereof:##STR4## wherein R₄ is as defined above, and

R₅ stands for a halogen atom or an azido, acetoxy or benzimidazolylthiogroup,

with the above-mentioned novel thioester (I).

Heretofore, cephalosporin derivatives represented by the general formula(V) have been prepared from 7-aminocephalosporanic acid or7-methoxy-7-aminocephoalosporanic acid through two steps. For example,there have been prepared cephalosporin derivatives represented by thegeneral formula (V) according to a process in which7-methoxy-7-(cyanomethylthioacetamido)-cephalosporanic acid firstproduced by reacting 7-methoxy-7-aminocephalosporanic acid withcyanomethylthioacetic acid (see Japanese Patent Application Laid-OpenSpecification No. 65790/76) and this acid thus produced is then reactedwith a 1-methyl-1,2,3,4-tetrazol-5-thiol to form a compound representedby the general formula (V) (see Japanese Patent Application Laid-OpenSpecification No. 65791/76), or a process in which7-methoxy-7-amino-3-(1-methyl-1,2,3,4-tetrazol-5-ylthiomethyl)-cephalosporanicacid is first produced by reacting 7-methoxy-7-aminocephalosporanic acidwith 1-methyl-1,2,3,4-tetrazol-5-thiol (see Japanese Patent PublicationNo. 17936/64) and this acid thus produced is then reacted withcyanomethylthioacetic acid to form a compound represented by the generalformula (V) (see Japanese Patent Application Laid-Open Specification No.65790/76). Also, when 7-aminocephalosporanic acid is used as a startingmaterial, cephalosporin derivatives represented by the general formula(V) have been prepared according to similar two-step processes to thoseas mentioned above.

Each of these two known processes comprises combination of twoindependent reactions, that is, acylation of the amino group at the7-position of 7-aminocephalosporanic acid or7-methoxy-7-aminocephalosporanic acid and substitution of the acetoxygroup of the 3-acetoxymethyl group with a thio group of a thiol or viceversa. The two independent reactions are quite different from each otherin reaction conditions, namely, the acylation reaction is carried out ina 50% aqueous solution of acetone at a temperature of 5° C. to roomtemperature while the substitution reaction is carried out in a 20 to30% aqueous solution of acetone at 60° C. Therefore, even if it isintended to conduct the two reactions in a continuous manner,interruption of the reaction cannot be avoided for changing the reactionconditions. Moreover, these two reactions are carried out under severeconditions for cephalosporin compounds with respect to their stability,namely, at a pH value of 6.5 to 7.0 and at 5° C. to room temperature for5 to 17 hours in the first stage of the two-stage process, and at a pHvalue of 6.5 to 7.5 and at 60° C. for 4 to 8 hours in the second stage.Such severe conditions affect the stability of cephalosporin compoundsand hence lead to low yields. Therefore, such processes are notpreferred from the economical viewpoint. In addition, if the reactionproduct obtained by practising the two-stage process in a continuousmanner is purified, an adverse effect of the unreacted startingcompounds and impurities such as compounds formed by decomposition uponthe purity of the product cannot be neglected, so that it will bedifficult to increase the purity of the product to a desired level.Moreover, methods heretofore used for acylation at the 7-position in theconventional processes, for example, the acid chloride method, the mixedacid anhydride method and the DCC condensation method, are remarkablydefective in workability and safety because the acylating agents used inthese methods decompose on contact with moisture and irritate humanskin. As apparent from the foregoing, the conventional processes are notsatisfactory from the commercial viewpoint.

In view of the current situation as mentioned above, the presentinventors have made intensive investigations on chemical reactivities ofthe above-mentioned novel thioesters and the process for the preparationthereof. As a result of the investigations, the present inventors foundthat these thioesters are very effective and valuable as acylatingagents for amines and hydrazines, for example, as active esters for thesynthesis of cephalosporin compounds in which the amino group at the7-position of 7-aminocephalosporin derivatives is acylated by the activeester and also found a process capable of preparing these thioestersvery simply. Furthermore the present inventors found that thesethioesters have such a reactivity that when they are reacted with7-aminocephalosporin derivatives, two substituents can be introducedinto the 7-aminocephalosporin derivatives to form cephalosporinderivatives represented by the above general formula (V) at a highefficiency without changing the reaction conditions or stopping thereaction in the midway. We have completed the present invention based onthese findings.

In accordance with one aspect of the present invention, there isprovided a novel thioester represented by the following general formula(I): ##STR5## wherein R₁, R₂ and R₃ are as defined above.

In accordance with another aspect of the present invention, there isprovided a process for the preparation of novel thioesters representedby the following general formula (I) which comprises reacting a thiolrepresented by the following general formula (II) or its derivative:

    H--R.sub.3                                                 (II)

wherein R₃ is as defined above,

with an acetic acid derivative represented by the following generalformula (III) or a reactive derivative thereof: ##STR6## wherein R₁ andR₂ are as defined above.

In accordance with still another aspect of the present invention, thereis provided a process for the preparation of a cephalosporin derivativesrepresented by the following general formula (V) or pharmacologicallyacceptable salts thereof: ##STR7## wherein R₁, R₂, R₃ and R₄ are asdefined above, which comprises reacting a 7-aminocephalosporanic acidderivative represented by the following general formula (IV) or a saltthereof: ##STR8## wherein R₄ and R₅ are as defined above, with acompound represented by the general formula (I).

The present invention will now be described in detail.

As the thioesters represented by the chemical formula (I), there can bementioned a 2-methyl-1,3,4-thiadiazol-5-ylthio ester ofp-hydroxyphenylglycine, a 1H-1,2,3-triazol-5-ylthio ester ofp-hydroxyphenylglycine, a 1-methyl-1,2,3,4-tetrazol-5-ylthio ester ofp-hydroxyphenylglycine, a 2-methyl-1,3,4-thiadiazol-5-ylthio ester ofN-carbobenzyloxy-p-hydroxyphenylglycine, a 1H-1,2,3-triazol-5-ylthioester of N-carbobenzyloxy-p-hydroxyphenylglycine, a1-methyl-1,2,3,4-tetrazol-5-ylthio ester ofN-carbobenzyloxy-p-hydroxyphenylglycine, a2-methyl-1,3,4-thiadiazol-5-ylthio ester ofN-formyl-p-hydroxyphenylglycine, a 1H-1,2,3-triazol-5-ylthio ester ofN-formyl-p-hydroxyphenylglycine, a 1-methyl-1,2,3,4,-tetrazol-5-ylthioester of N-formyl-p-hydroxyphenylglycine, a1-methyl-1,2,3,4-tetrazol-5-ylthio ester of trifluoromethylthioaceticacid, a 1-methyl-1,2,3,4-tetrazol-5-ylthio ester ofcyanomethylthioacetic acid, a 1-methyl-1,2,3,4-tetrazol-5-ylthio esterof 2-thienylacetic acid and a 1-methyl-1,2,3,4-tetrazol-5-ylthio esterof chloroacetic acid.

These thioesters are novel substances which have not been introduced inany of literature references, and they are valuable as acylating agentsfor amines and hydrazines, for example, as important reactants insynthesis of medical cephalosporin derivatives.

In the thioester compound of the present invention represented by thegeneral formula (I), since the thioester moiety ##STR9## is very high inthe reactivity, the thioester compound of the present invention canacylate easily amines or hydrazines, for example, an amino group at the7-position of a 7-aminocephalosporin derivative in high yield.Furthermore, the thioester compound of the present invention can act asa reagent for effecting substitution at the 3-position in such7-aminocephalosporin derivative.

More specifically, when 7-aminocephalosporanic acid is reacted with a1H-1,2,3-triazol-5-ylthio ester of N-formyl-p-hydroxyphenylglycine,acylation of the amino group at the 7-position is easily advanced at ahigh yield, and surprisingly, the acetoxy group at the 3-position issimultaneously substituted with 1H-1,2,3-triazole-5-thiol, with theresult that protection of the amino group is eliminated and7-(p-hydroxyphenylglycinamido)-3-(1H-1,2,3-triazol-5-ylthiomethyl)-3-cephem-4-carboxylicacid (Cefatrizine), which is valuable as an antibiotic substance havinga high microbial activity across abroad antimicrobial spectrum againstvarious microorganisms inclusive of Gram-positive and Gram-negativepathogenic bacteria, can be easily obtained in a high yield.

Furthermore, when7-methoxy-7-amino-3-(benzimidazolylthiomethyl)cephalosporanic acid issimilarly reacted with, for example, a1-methyl-1,2,3,4-tetrazol-5-ylthio ester of cyanomethylthioacetic acid,7-methoxy-7-(cyanomethylthioacetamido)-3-(1-methyl-1,2,3,4-tetrazol-5-ylthiomethyl)-3-cephem-4-carboxylicacid (Cefmetazole) can be easily obtained in a high yield.

Various active esters capable of acylating 7-aminocephalosporanic acidsare known. However, active esters capable of effecting acylation at ahigh conversion and simultaneously effecting substitution at the3-position at a high conversion with ease, such as the thioestercompounds of the present invention have not been known at all.Therefore, the thioesters of the present invention are epoch-making asactive esters for the acylation of 7-amiocephalosporanic acids.

Even when the 7-aminocephalosporin derivative of the formula (IV) inwhich the group R₅ bonded to the methyl group of the 3-position is anacetoxy group, a halogen atom or an azido group, the reaction issufficiently advanced in a neutral or weakly alkaline region, but if thegroup R₅ is a benzimidazolylthio group, this group is converted to aneliminated group having a very high reactivity in the presence of aproton and the substitution reaction is advanced very promptly in anacidic region where the cephalosporin compounds are stable. Accordingly,in this case, the reaction time can be shortened to 1/5, and the yieldis about 1.5 times. As the substituent of the same series to be bondedto the methyl group of the 3-position, there can be mentionedbenzthiazolylthio and benzoxazolylthio groups or the like. Even in caseof such substituent, the reaction is advanced, but thebenzimidazolylthio group is excellent in stability and reactivity.

The compounds of the following general formula (I) which are valuableand high in the reactivity as described above: ##STR10## wherein R₁, R₂and R₃ are as defined above, can easily be prepared in high yields byreacting a heterocyclic thiol represented by the following generalformula (II) or its derivative:

    H--R.sub.3                                                 (II)

wherein R₃ is as defined above,

with an acetic acid derivative represented by the following generalformula (III) or a reactive derivative thereof: ##STR11## wherein R₁ andR₂ are as defined above.

In the case where R₂ of the acetic acid derivative of the generalformula (III) is an amino group, the conversion is often highly improvedby protecting this amino group by an appropriate protecting group. Therecan be used protecting groups customarily used, for example, formyl,carbobenzyloxy, carbo-t-butyloxy and ethyl acetoacetate groups. If theamino group is thus protected, the protected group is removed aftercompletion of the reaction to obtain the intended compound.

As the derivative of the heterocyclic thiol of the general formula (II),there can be mentioned, for example, an alkali metal salt, a reactionproduct with a trialkyl aluminum, and a trialkylsilylated product.

As the reactive derivative of the acetic acid derivative represented bythe general formula (III), there can be mentioned acid halides, acidanhydrides, mixed acid anhydrides, acid amides, esters and acid azides.As specific examples, there can be mentioned acid chlorides, alkylcarbonate mixed anhydrides and aliphatic carboxylic acid (for example,pivalic acid, pentanoic acid, isopentanoic acid, 2-ethylbutanoic acid,trichloroacetic acid and trifluoroacetic acid) mixed anhydrides.Equimolar amount of the compound of the general formula (III) to theamount of the compound of the general formula (II) is sufficient forcarrying out the reaction successfully and the compound of the generalformula (III) may be used in an amount ranging from 0.8 to 2.0 mols permol of the compound of the general formula (II).

When free p-hydroxyphenylglycine,N-carbobenzyloxy-p-hydroxyphenylglycine orN-formyl-p-hydroxyphenylglycine is used as the reactant, a condensingagent is used for the reaction. As the condensing agent, there can bementioned, for example, N,N'-dicyclohexylcarbodiimide,N,N'-diisopropylcarbodiimide,N-cyclohexyl-N'-morpholinoethylcarbodiimide,N-cyclohexyl-N'-(4-diethylaminocyclohexyl)carbodiimide,N,N'-diethylcarbodiimide,N-ethyl-N'-(3-dimethylaminopropyl)-carbodiimide and trifluoroacetic acidanhydride. In this case, equimolar amount of the compound of the generalformula (III) to the amount of the compound of the general formula (II)is sufficient for carrying out the reaction successfully and thecompound of the general formula (III) may be used in an amount rangingfrom 0.8 to 1.2 mols per mol of the compound of the general formula(II). The amount of the condensing agent of 0.5 mols or more per mol ofthe compound of the general formula (II) is sufficient for carrying outthe reaction successfully. But it is preferred that the condensing agentbe used in an amount of 0.8 to 1.5 mols per mol of the compound of thegeneral formula (II) from the standpoint of efficiency, economy andpost-treatment.

The reaction can be carried out at temperatures in the broad range of,for example, -50° to 100° C., and the reaction may preferably be carriedout at -20° to 50° C.

The reaction may be carried out in a solvent. Any of solvents inert tothe reactants and capable of dissolving or dispersing the reactantstherein can be used. For example, there may be used ethers, esters,halogenated hydrocarbons and ketones. As specific examples, there can bementioned dioxane, ethyl acetate, methylene chloride, chloroform andacetone.

The reaction time may be varied depending on the reaction temperatureand the kind of the reactants to be used. Generally, 1 to 17 hours ispreferred.

After completion of the reaction, the intended compound is isolated fromthe reaction mixture and purified according to customary procedures. Forexample, the intended compound can easily be recovered by removing thesolvent by distillation, and washing and drying the residue.

A cephalosporin derivative represented by the general formula (V) or apharmacologically acceptable salt thereof can easily be obtained as thefinal intended compound at a high efficiency by reacting the so obtainedcompound of the general formula (I) with a compound represented by thegeneral formula (IV) in a solvent. It is sufficient if the amount of thecompound of the general formula (I) is at least equimolar to the amountof the compound of the general formula (IV). It is, however, preferredfrom the economical viewpoint that the compound of the general formula(I) be used in an amount of 1.0 to 2.0 mols per mol of the compound ofthe general formula (IV). As the solvent, there can be mentioned, forexample, amides such as N,N-dimethylformamide, N,N-diethylformamide,N,N-dimethylacetamide and N,N-diethylacetamide, alcohols such as methylalcohol and ethyl alcohol, aliphatic ketones such as acetone andmethylethyl ketone, ethers such as methyl cellosolve, halogenatedhydrocarbons such as dichloromethane and chloroform, nitriles such asacetonitrile and propionitrile, and sulfoxides such as dimethylsulfoxideand diethylsulfoxide. These solvents may be used singly or in the formof a mixture of two or more of them or an aqueous mixture. From theviewpoints of the dissolving power and the conversion and also from theeconomical viewpoint, it is preferred acetone acetonitrile, methylalcohol or an aqueous mixture thereof be used for 7-aminocephalosporanicacid and 7-methoxy-7-aminocephalosporanic acid, andN,N-dimethylformamide, N,N-dimethylacetamide or an aqueous mixturethereof be used for7-amino-3-(benzimidazol-2-yl)thiomethyl-3-cephem-4-carboxylic acid and7-methoxy-7-amino-3(benzimidazol-2-yl)thiomethyl-3-cephem-4-carboxylicacid.

As mentioned before, when a benzimidazolylthio compound, for example,7-amino-3-(benzimidazol-2-yl)thiomethyl-3-cephem-4-carboxylic acid isused as the compound represented by the general formula (IV), thereaction is carried out in the presence of an acid catalyst. However, inthe reaction system there is present not only a thiol compound formedfrom this compound but also a thiol compound formed by the substitutionreaction, and therefore, an acid catalyst need not particularly beadded. In order to shorten the reaction time and improve the conversion,however, it is preferred that an acid catalyst be added. As the acidcatalyst, there can be mentioned mineral acids such as hydrochloric acidand sulfuric acid, and organic acids, for example, sulfonic acids suchas p-toluenesulfonic acid, methanesulfonic acid, fatty acids such aspropionic acid, and thiols such as 1-methyl-tetrazol-5-thiol. From theviewpoints of increase of the yield and shortening of the reaction time,mineral acids and thiols are especially preferred.

The acid catalyst is ordinarily added in an amount of 0.05 to 1 mol permol of, for example,7-amino-3-(benzimidazol-2-yl)thiomethyl-3-cephem-4-carboxylic acid.

When the group R5 bonded to the methyl group at the 3-position of thegeneral formula (IV) is an acetoxy group, a halogen atom or an azidogroup, an alkaline substance, for example, sodium bicarbonate is addedin the reaction system so that the reaction is carried out in a neutralor weakly alkaline region (pH 7 to 8).

The reaction temperature may be varied according to the kind of thesolvent, but ordinarily, the reaction is sufficiently advanced at atemperature of 10° to 100° C. From the viewpoints of the conversion andthe stability of the cephalosporin skeleton, it is especially preferredthat the reaction be carried at a temperature of 40° to 80° C.

The reaction time may be varied according to the kind of the group R₅bonded to the methyl group at the 3-position of the general formula (IV)and the kind of the solvent, it is ordinarily sufficient if the reactionis conducted for 30 minutes to 10 hours. For example, when7-amino-3-(benzimidazol-2-yl)thiomethyl-3-cephem-4-carboxylic acid isused and the reaction is carried out in water-containingN,N-dimethylformamide as the solvent at 60° C. in the presence of anacid catalyst, a reaction time of 30 minutes to 3 hours is sufficient.When acylation at the 7-position and substitution at the 7-position areconducted in a continuous manner according to the conventional process,8 to 18 hours are necessary for completion of the reaction, and sidereactions of the product with the reactants and decomposition of theproduct are caused. In view of this fact, it will readily be understoodthat the process of the present invention is very simple andeconomically advantageous.

In the present invention, the so obtained cephalosporin compoundrepresented by the general formula (V) may be converted to apharmacologically acceptable salt according to need. Namely, thecephalosporin compound can be converted to an alkali metal salt, anammonium salt or an alkaline earth metal salt according to customaryprocedures. In preparing pharmaceuticals, these salts are especiallyadvantageous because of their high water solubilities.

The thioester compound of the general formula (I) according to thepresent invention is a brownish yellow compound and has none of themoisture-absorbing property, irritating property and corrosive action.Accordingly, this thioester compound can easily be handled with safety,and the working environment and apparatus are not impaired by thiscompound at all, and high operation safety can be maintained assuredly.Accordingly, from the practical viewpoint, the compound of the presentinvention is excellent over the conventional compounds used forsynthesis of cephalosporin compounds, and according to the presentinvention, cephalosporin compounds of the general formula (V), which areexcellent antibiotic substances having a high antimicrobial activity,and pharmacologically acceptable salts thereof can be prepared in highyields very safely.

For the treatment of infection, the compounds produced by a processaccording to the present invention are preferably administered orally orparenterally, as is conventional for the administration of antibiotics;preferred formulations are tablets, capsules, injectible liquids andsuspensions. The daily dosage of the compounds produced by a processaccording to the present invention will, naturally, vary depending uponthe age, condition and body weight of the patient. However, thecompounds will normally be administered in divided doeses of from about250 mg to about 3,000 mg per day for adults, normally two or four timesa day.

The present invention will now be described in detail with reference tothe following Examples that by no means limit the scope of theinvention.

EXAMPLE 1

In a 1-liter eggplant type flask equipped with a drying calcium chloridetube were charged 8.4 g of p-hydroxyphenylglycine, 6.6 g of2-methyl-1,3,4-thiadiazol-5-thiol and 500 ml of ethyl acetate, and themixture was stirred to form a solution. Then, 10.3 g ofN,N'-dicyclohexylcarbodiimide was added to the solution and the mixturewas stirred at 25° C. for 12 hours. The resulting reaction mixture wassubjected to filtration to remove insoluble N,N'-dicyclohexylurea. Thefiltrate was distilled under reduced pressure and the obtained oilysubstance was dissolved in a small amount of ethyl acetate and thencrystallized from a small amount of n-hexane. Filtration and drying werecarried out according to customary procedures to obtain 6.2 g of a2-methyl-1,3,4-thiadiazol-5-yl-thio ester of p-hydroxyphenylglycine inthe form of brown crystals (the yield was 44%).

    ______________________________________                                        Elementary Analysis                                                                             Calculated                                                                              Found                                             ______________________________________                                        C                 47.0%     46.5%                                             H                  3.9%      4.9%                                             N                 14.9%     14.1%                                             C                 22.8%     22.0%                                             Mass Spectrum (m/e)                                                           M.sup.+ 281                                                                   ______________________________________                                    

EXAMPLE 2

In a 2-liter egglant type flask equipped with a drying calcium chloridetube were charged 30.1 g of p-hydroxy-N-carbobenzyloxyphenylglycine and13.2 g of 2-methyl-1,3,4-thiadiazol-5-thiol and 1 liter of dry acetone,and the mixture was stirred to form a solution. Then 20.6 g ofN,N'-dicyclohexylcarbodiimide was added to the solution and the mixturewas stirred at 25° C. for 15 hours. The resulting reaction mixture wassubjected to filtration to remove insoluble N,N'-dicyclohexylurea. Thefiltrate was distilled under reduced pressure and the obtained oilysubstance was subjected to removal of the carbobenzyloxy group withhydrobromic acid according to customary procedures. The product wasextracted with ethyl acetate and the solvent was removed by distillationunder reduced pressure, and the residue was recrystallized from acetoneto obtain 12.9 g of a 2-methyl-1,3,4-thiadiazol-5-ylthio ester ofp-hydroxyphenylglycine in the form of brown crystals (the yield was45.9%).

EXAMPLE 3

Substantially the same procedures as in Example 2 were repeated exceptthat 10.1 g of 1H-1,2,3-triazol-5-thiol was used instead of2-methyl-1,3,4-thiadiazol-5-thiol, to obtain 11.9 g of a1H-1,2,3-triazol-5-ylthio ester of p-hydroxyphenylglycine in the form ofbrown crystals (the yield was 47.6%).

    ______________________________________                                        Elementary Analysis                                                                             Calculated                                                                              Found                                             ______________________________________                                        C                 48.0%     47.2%                                             H                  4.0%      5.1%                                             N                 22.4%     21.9%                                             S                 12.8%     12.2%                                             Mass Spectrum (m/e)                                                           M.sup.+ 250                                                                   ______________________________________                                    

EXAMPLE 4

Substantially the same procedure as in Example 1 were repeated exceptthat 5.8 g of 1-methyltetrazol-5-thiol was used instead of2-methyl-1,3,4-thiadiazol-5-thiol to obtain 6.9 g of a1-methyltetrazol-5-thio ester of p-hydroxyphenylglycine in the form ofbrown crystals (the yield was 52.1%).

EXAMPLE 5

Substantially the same procedures as in Example 1 were repeated in thesame manner except that 9.8 g of p-hydroxy-N-formylphenylglycine wasused instead of p-hydroxyphenylglycine and a compound shown in Table 1was used instead of 2-methyl-1,3,4-thiadiazol-5-thiol. The obtainedresults are shown in Tables 1 and 2.

                  TABLE 1                                                         ______________________________________                                        Starting Compound                                                                            Product                                                        Run  Thiol         Amount (g)                                                                              Amount (g)                                                                            Yield (%)                                ______________________________________                                        a    2-methyl-1,3,4-                                                                             6.6       13.1    85                                            thiadiazol-5-thiol                                                       b    1H--1,2,3-triazol-5-                                                                        5.5       11.5    83                                            thiol                                                                    c    1-methyl-1,2,3,4-                                                                           5.8       12.7    87                                            tetrazol-5-thiol                                                         ______________________________________                                    

                  TABLE 2                                                         ______________________________________                                                                   Mass                                                            Elementary Analysis (%)                                                                     Spectrum                                           Run  Compound      C      H    N    S    (m/e), M.sup.+                       ______________________________________                                        a    2-methyl-1,3,4-                                                                             46.60  3.56 13.59                                                                              20.71                                                                              309                                       thiadiazol-5-thio                                                                           (calculated)                                                    ester of p-hydroxy-                                                                         46.52  3.73 13.53                                                                              20.61                                          N--formylphenyl-                                                                            (found)                                                         glycine                                                                  b    1H--1,2,3-triazol-                                                                          47.48  3.60 20.14                                                                              11.51                                                                              278                                       5-thio ester of                                                                             (calculated)                                                    p-hydroxy-N--for-                                                                           47.42  3.66 20.00                                                                              11.29                                          mylphenylglycine                                                                            (found)                                                    c    1,2,3,4-tetrazol-                                                                           45.05  3.75 23.89                                                                              10.92                                                                              293                                       5-thio ester of                                                                             (calculated)                                                    p-hydroxy-N--for-                                                                           44.96  3.92 23.66                                                                              10.67                                          mylphenylglycine                                                                            (found)                                                    ______________________________________                                    

EXAMPLE 6

A 1-liter eggplant type flask equipped with a drying calcium chloridetube was charged with 8.4 g of p-hydroxyphenylglycine and 5.1 g of1H-1,2,3-triazol-5-thiol, and 400 ml of dry acetone was added and themixture was stirred to form a solution. Then, 10.3 g ofN,N'-dicyclohexylcarbodiimide was added and the mixture was stirred at25° C. for 6 hours. The resulting reaction mixture was subjected tofiltration to remove insoluble N,N'-dicyclohexylurea. The filtrate wasdistilled under reduced pressure and the obtained oily substance wasdissolved in a small amount of ethyl acetate and then crystallized froma small amount of n-hexane. Filtration and drying were carried outaccording to customary procedures to obtain 5.3 g of a1H-1,2,3-triazol-5-ylthio ester of p-hydroxyphenylglycine (the yield was43%).

    ______________________________________                                        Elementary Analysis                                                                             Calculated                                                                              Found                                             ______________________________________                                        C                 48.00     47.12                                             H                  4.00      4.69                                             N                 22.40     21.93                                             S                 12.80     12.61                                             Mass Spectrum (m/e)                                                           M.sup.+ 250                                                                   ______________________________________                                    

EXAMPLE 7

Substantially the same procedures as in Example 2 were repeated exceptthat 11.6 g of 1-methyl-1,2,3,4-tetrazol-5-thiol was used instead of2-methyl-1,3,4-thiadiazol-5-thiol, to obtain 11.5 g of a1-methyl-1,2,3,4-tetrazol-5-ylthio ester of p-hydroxyphenylglycine inthe form of a brown solid (the yield was 43.4%).

EXAMPLE 8

A 2-liter egglant type flask equipped with a drying calcium chloridetube was charged with 30.1 g of p-hydroxyphenyl-N-carbobenzyloxyglycineand 13.2 g of 2-methyl-1,3,4-thiadiazol-5-thiol, and 1 liter of dryacetone was added and the mixture was stirred to form a solution. Then,20.6 g of N,N'-dicyclohexylcarbodiimide was added to the solution andthe mixture was stirred at 25° C. for 20 hours. The resulting reactionmixture was subjected to filtration to remove insolubleN,N'-dicyclohexylurea. The solvent was removed from the filtrate bydistillation under reduced pressure and the residue was dissolved in dryethyl acetate. A small amount of n-hexane was added to the solution toeffect crystallization, and the crystallization product was dried toobtain 31.54 g of a 2-methyl-1,3,4-thiadiazol-5-ylthio ester ofN-carbobenzyloxy-p-hydroxyphenylglycine in the form of a brown solid(the yield was 76%).

    ______________________________________                                        Elementary Analysis                                                                             Calculated                                                                              Found                                             ______________________________________                                        C                 54.94%    54.66%                                            H                  4.10%     4.21%                                            N                 10.12%    10.06%                                            S                 15.42%    15.33%                                            Mass Spectrum (m/e)                                                           M.sup.+ 415                                                                   ______________________________________                                    

EXAMPLE 9

Substantially the same procedures as in Example 8 were repeated exceptthat a thiol shown in Table 3 was used instead of2-methyl-1,3,4-thiadiazol-5-thiol. The obtained results are shown inTables 3 and 4.

                  TABLE 3                                                         ______________________________________                                        Starting Compound                                                                            Product                                                        Run  Thiol         Amount (g)                                                                              Amount (g)                                                                            Yield (%)                                ______________________________________                                        a    1H--1,2,3-triazol-5-                                                                        10.1      28.4    74                                            thiol                                                                    b    1-methyl-1,2,3,4-                                                                           11.6      27.1    68                                            tetrazol-5-thiol                                                         ______________________________________                                    

                  TABLE 4                                                         ______________________________________                                                                   Mass                                                            Elementary Analysis (%)                                                                     Spectrum                                           Run  Compound      C      H    N    S    (m/e), M.sup.+                       ______________________________________                                        a    1H--1,2,3-triazol-5-                                                                        56.25  4.17 14.58                                                                              8.33 384                                       ylthio ester of N--                                                                         (calculated)                                                    carbobenzyloxy-p-                                                                           56.01  4.52 14.11                                                                              8.07                                           hydroxyphenyl (found)                                                         glycine                                                                  b    1-methyl-1,2,3,4-                                                                           54.14  4.26 17.54                                                                              8.02 399                                       tetrazol-5-ylthio                                                                           (calculated)                                                    ester of N--carbo-                                                                          53.98  4.53 17.49                                                                              7.92                                           benzyloxy-p-  (found)                                                         hydroxyphenylgly-                                                             cine                                                                     ______________________________________                                    

EXAMPLE 10

A 1-liter eggplant type flask equipped with a drying calcium chloridetube was charged with 16.0 g of trifluoromethylthioacetic acid and 11.6g of 1-methyl-tetrazol-5-thiol, and 500 ml of dry ethyl acetate wasadded and the mixture was stirred to form a solution. Then, 20.6 g ofN,N'-dicyclohexylcarbodiimide was added to the solution and the mixturewas stirred at 25° C. for 12 hours. The resulting reaction mixture wassubjected to filtration to remove insoluble N,N'-dicyclohexylurea. Thefiltrate was distilled under reduced pressure, and the obtained oilysubstance was dissolved in a small amount of ethyl acetate and thencrystallized from a small amount of n-hexane. Filtration and drying werecarried out according to customary procedures to obtain 20.8 g of a1-methyltetrazol-5-ylthio ester of trifluoromethylthioacetic acid in theform of dark brown crystals (the yield was 81%).

    ______________________________________                                        Elementary Analysis                                                                             Calculated                                                                              Found                                             ______________________________________                                        C                 23.3%     23.2%                                             N                 21.7%     21.9%                                             S                 24.8%     24.7%                                             F                 22.1%     22.1%                                             H                  1.9%      1.9%                                             Mass Spectrum (m/e)                                                           M.sup.+ 258                                                                   ______________________________________                                    

EXAMPLE 11

A 300-ml eggplant type flask equipped with a drying calcium chloridetube was charged with 3.2 g of trifluoromethylthioacetic acid and 1.35 gof 1-methyltetrazol-5-thiol, and 200 ml of dry acetone was added and themixture was stirred to form a solution. Then, 4.12 g ofN,N'-dicyclohexylcarbodiimide was added to the solution and the mixturewas stirred at 25° C. for 15 hours. The resulting reaction mixture wassubjected to filtration to remove insoluble N,N'-dicyclohexylurea. Thefiltrate was distilled under reduced pressure and the obtained oilysubstance was dissolved in a small amount of ethyl acetate, and thesolution was allowed to stand in a refrigerator for 15 hours to formcrystals. The crystals was recovered by filtration and dried accordingto customary procedures to obtain 3.92 g of a 1-methyltetrazol-5-ylthioester of trifluoromethylthioacetic acid in the form of dark browncrystals (the yield was 76%).

EXAMPLE 12

A 500 ml eggplant type flask equipped with a drying calcium chloridetube was charged with 6.55 g of cyanomethylthioacetic acid and 5.8 g of1-methyltetrazol-5-thiol, and 300 ml of dry ethyl acetate was added andthe mixture was stirred to form a solution. Then, 10.3 g ofN,N'-dicyclohexylcarbodiimide was added to the solution, and the mixturewas stirred at 25° C. for 14 hours. The resulting reaction mixture wassubjected to filtration to remove insoluble N,N'-dicyclohexylurea. Thefiltrate was distilled under reduced pressure, and the obtained oilysubstance was dissolved in a small amount of ethyl acetate and thencrystallized from a small amount of n-hexane. The crystals wererecovered by filtration and dried according to customary procedures toobtain 9.5 g of a 1-methyltetrazol-5-ylthio ester ofcyanomethylthioacetic acid in the form of dark yellow crystals (theyield was 83%).

    ______________________________________                                        Elementary Analysis                                                                             Calculated                                                                              Found                                             ______________________________________                                        C                 31.4%     31.2%                                             N                 30.6%     30.7%                                             S                 27.9%     27.7%                                             H                  3.1%      3.3%                                             Mass Spectrum (m/e)                                                           M.sup.+ 229                                                                   ______________________________________                                    

EXAMPLE 13

A 1-liter eggplant type flask equipped with a drying calcium chloridetube was charged with 13.1 g of cyanomethylthioacetic acid and 11.6 g of1-methyltetrazol-5-thiol, and 600 ml of dry acetone was added and themixture was stirred to form a solution. Then, 20.6 g ofN,N'-dicyclohexylcarbodiimide was added to the solution and the mixturewas stirred at 25° C. for 15 hours. The resulting reaction mixture wassubjected to filtration to remove insoluble N,N'-dicyclohexylurea. Thefiltrate was distilled under reduced pressure, and the obtained oilysubstance was dissolved in a small amount of ethyl acetate and thencrystallized from a small amount of n-hexane. The crystals wererecovered by filtration and dried according to customary procedures toobtain 19.5 g of a 1-methyltetrazol-5-ylthio ester ofcyanomethylthioacetic acid in the form of dark yellow crystals (theyield was 85%).

EXAMPLE 14

A 1-liter eggplant type flask equipped with a drying calcium chloridetube was charged with 14.2 g of 2-thienylacetic acid and 11.6 g of1-methyltetrazol-5-thiol, and 700 ml of dry ethyl acetate was added andthe mixture was stirred to form a solution. Then, 20.6 g ofN,N'-dicyclohexylcarbodiimide was added to the solution and the mixturewas stirred at 25° C. for 12 hours. The resulting reaction mixture wassubjected to filtration to remove insoluble N,N'-dicyclohexylurea. Thefiltrate was distilled under reduced pressure, and the obtained oilysubstance was dissolved in a small amount of ethyl acetate and thencrystallized from a small amount of n-hexane. The crystals wererecovered by filtration and dried according to customary procedures toobtain 19.0 g of a 1-methyltetrazol-5-ylthio ester of 2-thienylaceticacid in the form of brown crystals (the yield was 79%).

    ______________________________________                                        Elementary Analysis                                                                             Calculated                                                                              Found                                             ______________________________________                                        C                 40.0%     40.1%                                             N                 23.3%     23.2%                                             S                 26.7%     26.8%                                             H                  3.3%      3.3%                                             Mass Spectrum (m/e)                                                           M.sup.+ 240                                                                   ______________________________________                                    

EXAMPLE 15

A 2-liter eggplant type flask equipped with a drying calcium chloridetube was charged with 18.9 g of 2-chloroacetic acid and 23.2 g of1-methyltetrazol-5-thiol, and 1 liter of dry acetone was added and themixture was stirred to form a solution. Then, 41.2 g ofN,N'-dicyclohexylcarbodiimide was added to the solution and the mixturewas stirred at 25° C. for 12 hours. The resulting reaction mixture wassubjected to filtration to remove insoluble N,N'-dicyclohexylurea. Thefiltrate was distilled under reduced pressure, and the obtained oilysubstance was dissolved in a small amount of ethyl acetate and thencrystallized from a small amount of n-hexane. The crystals wererecovered by filtration and dried according to customary procedures toobtain 30.8 g of a 1-methyltetrazol-5-ylthio ester of 2-chloroaceticacid in the form of brown crystals.

    ______________________________________                                        Elementary Analysis                                                                             Calculated                                                                              Found                                             ______________________________________                                        C                 35.60%    35.52%                                            H                 3.21%     3.43%                                             N                 20.77%    20.71%                                            S                 15.82%    15.77%                                            Cl                8.78%     8.76%                                             Mass Spectrum (m/e)                                                           M.sup.+2 194                                                                  ______________________________________                                    

EXAMPLE 16

2.7 g of 7-aminocephalosporanic acid was charged into a 300 mlthree-necked flask and then dissolved in 100 ml of an aqueous solutionof sodium hydrogencarbonate so that the resulting solution had a pHvalue of 7.0 to 7.5. A solution of 3.0 g of a2-methyl-1,3,4-thiadiazol-5-ylthio ester of p-hydroxyphenylglycine in 50ml of acetone was dropped into the three-necked flask over a period of15 minutes at room temperature. The resulting mixture was heated at 60°C. and stirred for 7 hours while adding sodium hydrogencarbonate so thatthe pH value of the liquid was maintained at 6.8. After completion ofthe reaction, the acetone was removed by distillation under reducedpressure and the resulting concentrate was subjected to fractionalhigh-speed liquid chromatography to obtain a fraction of the intendedproduct. The fraction was concentrated under reduced pressure to obtain29 g of7-(p-hydroxyphenylglycinamido)-3-(2-methyl-1,3,4-thiadiazol-5-yl)thiomethylcephalosporanicacid in the form of a yellow powder (the yield was 60%). The product hada purity of 80%.

    ______________________________________                                        Conditions for Fractional High-Speed Liquid Chromatography                    ______________________________________                                        Chromatograph:                                                                              System Model 500 supplied by Waters                                           Assoc. Co.                                                      Solvent:      methanol/water (40/60 by volume)                                Column:       fractional column, Prep-PAK C18                                 Flow rate:    100 ml/min                                                      ______________________________________                                    

EXAMPLE 17

3.6 g of 7-amino-3-(benzimidazol-2-yl)thiomethylcephalosporanic acid wascharged into a 500-ml three-necked flask and then dissolved in 100 ml ofan aqueous solution of sodium hydrogencarbonate so that the resultingsolution had a pH value of 7.0 to 7.5. A solution of 2.7 g of a1H-1,2,3-triazol-5-ylthio ester of p-hydroxyphenylglycine in 50 ml ofdimethylformamide was dropped into the three-necked flask over a periodof 15 minutes at room temperature. The pH value of the resulting mixturewas adjusted to 4.1 by diluted hydrochloric acid, and the mixture washeated at 60° C. and stirred for 2 hours. After completion of thereaction, the resulting reaction mixture was subjected to fractionalhigh-speed liquid chromatography to obtain a fraction of the intendedproduct. The fraction was concentrated under reduced pressure andfreeze-dried to obtain 3.7 g of7-(p-hydroxyphenylglycinamido)-3-(1H-1,2,3-triazol-5-yl)thiomethylcephalosporanicacid in the form of a white solid (the yield was 81%). The product had apurity of 91%.

    ______________________________________                                        Conditions for Fractional High-Speed Liquid Chromatography                    ______________________________________                                        Chromatograph:                                                                              System Model 500 supplied by Waters                                           Assoc. Co.                                                      Solvent:      methanol/water (40/60 by volume)                                Column:       fractional column, Prep-PAK C18                                 Flow rate:    100 ml/min                                                      ______________________________________                                    

EXAMPLE 18

3.6 g of 7-amino-3-(benzimidazol-2-yl)thiomethylcephalosporanic acid wascharged into a 300-ml three-necked flask and then dissolved in 100 ml ofan aqueous solution of sodium hydrogencarbonate so that the resultingsolution had a pH value of 7.0 to 7.5. A solution of 3.0 g of a1H-1,2,3-triazol-5-ylthio ester of p-hydroxy-N-formylphenylglycine in 50ml of dimethylformamide was dropped into the thre-necked flask over aperiod of 15 minutes at room temperature. The pH value of the liquidmixture was adjusted to 4.1 by diluted hydrochloric acid, and themixture was heated at 60° C. and stirred for 1 hour. Then, the pH valueof the resulting reaction mixture was adjusted to 8.0 by sodiumhydrogencarbonate to effect deformylation. After completion of thedeformylation, the liquid reaction mixture was directly subjected tofractional high-speed liquid chromatography to obtain a fraction of theintended product. The fraction was concentrated under reduced pressureand freeze-dried to obtain 3.7 g of7-(p-hydroxyphenylglycinamido)-3-(1H-1,2,3-triazol-5-yl)thiomethylcephalosporanicacid in the form of a white solid (the yield was 85%). The product had apurity of 93%.

Conditions for the fractional high-speed liquid chromatography were thesame as those adopted in Example 17.

EXAMPLE 19

Substantially the same procedures as in Example 18 were repeated exceptthat a compound shown in Table 5 was used instead of the1H-1,2,3-triazol-5-ylthio ester of p-hydroxy-N-formylphenylglycine. Theobtained results are shown in Table 5.

                                      TABLE 5                                     __________________________________________________________________________    Starting Compound Product                                                                 Amount        Amount                                                                              Yield                                                                             Purity                                    Run Kind    (g)   Kind    (g)   (%) (%)                                       __________________________________________________________________________    a   2-methyl-                                                                             3.3   7-(p-hydroxy-                                                                         4.3   87  95                                            1,3,4-thia-   phenylglycyl)-                                                  diazol-5-     amido-3-(2-                                                     ylthio ester  methyl-1,3,4-                                                   of p-hydroxy- thiadiazol-5-                                                   N--formyl-    yl)thiomethyl-                                                  phenylglycine cephalosporanic                                                               acid                                                        b   1-methyl-                                                                             3.2   7-(p-hydroxy-                                                                         4.0   83  92                                            1,2,3,4-tetra-                                                                              phenylglycyl)-                                                  zol-5-ylthio  amido-3-(1-                                                     ester of p-   methyl-1,2,3,4-                                                 hydroxy-N--   tetrazol-5-yl)                                                  formylphenyl- thiomethyl-                                                     glycine       cephalosporanic                                                               acid                                                        __________________________________________________________________________

EXAMPLE 20

3.6 g of 7-amino-3-(benzimidazol-2-yl)thiomethylcephalosporanic acid wascharged into a 300-ml three-necked flask, and then dissolved in 100 mlof an aqueous solution of sodium hydrogencarbonate so that the resultingsolution had a pH value of 7.0 to 7.5. A solution of 4.0 g of a1H-1,2,3-triazol-5-ylthio ester ofN-carbobenzyloxy-p-hydroxyphenylglycine in 50 ml of dimethylformamidewas dropped into the three-necked flask over a period of 15 minutes atroom temperature. The pH value of the liquid mixture was adjusted to 4.1by diluted hydrochloric acid, and the mixture was heated at 60° C. andstirred for 1.5 hours. After completion of the reaction, the pH value ofthe resulting reaction mixture was adjusted to 2.0 by hydrochloric acidand the reaction mixture was extracted with ethyl acetate. The ethylacetate was removed from the extract by distillation under reducedpressure and the residue was dissolved in an aqueous solution ofhydrobromic acid and the solution was stirred at room temperature for 5hours. After completion of the reaction, the resulting reaction mixturewas subjected to fractional high-speed liquid chromatography to obtain afraction of the intended product. The fraction was concentrated underreduced pressure and freeze-dried to obtain 3.9 of7-(p-hydroxyphenylglycinamido)-3-(1H-1,2,3-triazol-5-yl)thiomethylcephalosporanicacid in the form of a white solid (the yield was 85%). The product had apurity of 93%.

    ______________________________________                                        Conditions for Fractional High-Speed Liquid Chromatography                    ______________________________________                                        Chromatograph:                                                                              System Model 500 supplied by Waters                                           Assoc. Co.                                                      Solvent:      methanol/water (40/60 by volume)                                Column:       fractional column, Prep-PAK C18                                 Flow rate:    100 ml/min                                                      ______________________________________                                    

EXAMPLE 21

3.0 g of 7-methoxy-7-aminocephalosporanic acid was charged into a 300-mlthree-necked flask, and then dissolved in 100 ml of an aqueous solutionof sodium hydrogencarbonate so that the resulting solution had a pHvalue of 7.0 to 7.5. A solution of 3.0 g of a2-methyl-1,3,4-thiadiazol-5-ylthio ester of p-hydroxyphenylglycine in 50ml of acetone was dropped into the three-necked flask over a period of15 minutes at room temperature. The liquid mixture was heated at 60° C.and stirred for 7 hours while adding sodium hydrogencarbonate so thatthe pH value of the liquid mixture was maintained at 6.8. Aftercompletion of the reaction, the acetone was removed by distillationunder reduced pressure and the residue was subjected to fractionalhigh-speed liquid chromatography to obtain a fraction of the intendedproduct. The fraction was concentrated under reduced pressure to obtain2.7 g of7-(p-hydroxyphenylglycinamido)-7-methoxy-3-(2-methyl-1,2,4-thiadiazol-5-yl)thiomethylcephalosporanicacid in the form of a yellow powder (the yield was 52%). The product hada purity of 80%.

    ______________________________________                                        Conditions for Fractional High-Speed Liquid Chromatography                    ______________________________________                                        Chromatograph:                                                                              System Model 500 supplied by Waters                                           Assoc. Co.                                                      Solvent:      methanol/water (40/60 by volume)                                Column:       fractional column, Prep-PAK C18                                 Flow rate:    100 ml/min                                                      ______________________________________                                    

EXAMPLE 22

3.9 g of7-methoxy-7-amino-3-(benzimidazol-2-yl)thiomethylcephalosporanic acidwas charged into a 300-ml three-necked flask, and then dissolved in 100ml of an aqueous solution of sodium hydrogencarbonate so that theresulting solution had a pH value of 7.0 to 7.5. A solution of 2.7 g ofa 1H-1,2,3-triazol-5-ylthiol ester of p-hydroxyphenylglycine in 50 ml ofdimethylformamide was dropped into the three-necked flask over a periodof 15 minutes at room temperature. The pH value of the liquid mixturewas adjusted to 4.1 by diluted hydrochloric acid, and the mixture washeated at 60° C. and stirred for 1 hour. After completion of thereaction, the liquid reaction mixture was subjected to fractionalhigh-speed liquid chromatography to obtain a fraction of the intendedproduct, and the fraction was concentrated under reduced pressure andfreeze-dried to obtain 3.1 g of7-(p-hydroxyphenylglycinamido)-7-methoxy-3-(1H-1,2,3-triazol-5-yl)thiomethylcephalosporanicacid in the form of a white solid (the yield was 61%). The product had apurity of 91%.

    ______________________________________                                        Conditions for Fractional High-Speed Liquid Chromatography                    ______________________________________                                        Chromatograph:                                                                              System Model 500 supplied by Waters                                           Assoc. Co.                                                      Solvent:      methanol/water (40/60 by volume)                                Column:       fractional column, Prep-PAK C18                                 Flow rate:    100 ml/min                                                      ______________________________________                                    

EXAMPLE 23

3.9 g of7-methoxy-7-amino-3-(benzimidazol-2-yl)thiomethylcephalosporanic acidwas charged into a 300-ml three-necked flask, and then dissolved in 100ml of an aqueous solution of sodium hydrogencarbonate so that theresulting solution had a pH value of 7.0 to 7.5. A solution of 3.0 g ofa 1H-1,2,3-triazol-5-ylthiol ester of p-hydroxy-N-formylphenylglycine in50 ml of dimethylformamide was dropped into the three-necked flask overa period of 15 minutes at room temperature. The pH value of the liquidmixture was adjusted to 4.1 by diluted hydrochloric acid, and themixture was heated at 60° C. and stirred for 1 hour. The pH value of thereaction mixture was adjusted to 8.0 by sodium hydrogencarbonate toeffect deformylation. After completion of the deformylation, thereaction mixture was directly subjected to fractional high-speed liquidchromatography to obtain a fraction of the intended product. Thefraction was concentrated under reduced pressure and freeze-dried toobtain 4.3 g of 7-(p-hydroxyphenylglycinamido)-7-methoxy-3-(1H-triazol-5-yl)thiomethylcephalosporanic acid in the form of a whitesolid (the yield was 85%). The product had a purity of 93%.

Conditions for the fractional high-speed liquid chromatography were thesame as those adopted in Example 22.

EXAMPLE 24

Substantially the same procedures as in Examples 23 were repeated exceptthat a compound shown in Table 6 was used instead of the1H-1,2,3-triazol-5-ylthiol ester of p-hydroxy-N-formylphenylglycine. Theobtained results are shown in Table 6.

                                      TABLE 6                                     __________________________________________________________________________    Starting Compound Product                                                                 Amount        Amount                                                                              Yield                                                                             Purity                                    Run Kind    (g)   Kind    (g)   (%) (%)                                       __________________________________________________________________________    a   2-methyl-                                                                             3.3   7-(p-hydroxy-                                                                         4.6   87  95                                            1,3,4-thiadia-                                                                              phenylglycyl-                                                   zol-5-ylthio  amido)-7-                                                       ester of p-   methoxy-3-(2-                                                   hydroxy-N--   methyl-1,3,4-                                                   formylphenyl- thiadiazol-5-                                                   glycine       yl)thiomethyl-                                                                cephalosporanic                                                               acid                                                        b   1-methyl-                                                                             3.2   7-(p-hydroxy-                                                                         4.3   83  92                                            1,2,3,4-tetra-                                                                              phenylglycyl-                                                   zol-5-ylthio  amido)-7-                                                       ester of p-   methoxy-3-(1-                                                   hydroxy-N--   methyl-1,2,3,4-                                                 formylphenyl- tetrazol-5-yl)-                                                 glycine       thiomethyl-                                                                   cephalosporanic                                                               acid                                                        __________________________________________________________________________

EXAMPLE 25

3.9 g of7-methoxy-7-amino-3-(benzimidazol-2-yl)thiomethylcephalosporanic acidwas charged into a 300-ml three-necked flask was charged with, and thendissolved in 100 ml of an aqueous solution of sodium hydrogencarbonateso that the resulting solution had a pH value of 7.0 to 7.5. A solutionof 4.0 g of a 1H-1,2,3-triazol-5-ylthio ester ofN-carbobenzyloxy-p-hydroxyphenylglycine in 50 ml of dimethylformamidewas dropped into the three-necked flask over a period of 15 minutes atroom temperature. The pH value of the resulting mixture was adjusted to4.1 by diluted hydrochloric acid, and the mixture was heated at 60° C.and stirred for 15 hours. After completion of the reaction, the pH valueof the reaction mixture was adjusted to 2.0 by hydrochloric acid andthen the reaction mixture was extracted with ethyl acetate. The ethylacetate was removed from the extract by distillation under reducedpressure, and the residue was dissolved in an aqueous solution ofhydrobromic acid and the solution was stirred at room temperature for 5hours. After completion of the reaction, the reaction mixture wassubjected to fractional high-speed liquid chromatography to obtain afraction of the intended product. The fraction was concentrated underreduced pressure and freeze-dried to obtain 4.2 g of7-(p-hydroxyphenylglycinamido)-7-methoxy-3-(1H-1,2,3-triazol-5-yl)thiomethylcephalosporanicacid in the form of a white solid (the yield was 85%). The product had apurity of 93%.

    ______________________________________                                        Conditions for Fractional High-Speed Liquid Chromatography                    ______________________________________                                        Chromatograph:                                                                              System Model 500 supplied by Waters                                           Assoc. Co.                                                      Solvent:      methanol/water (40/60 by volume)                                Column:       fractional column, Prep-PAK C18                                 Flow rate:    100 ml/min                                                      ______________________________________                                    

EXAMPLE 26

A 2-liter three-necked flask equipped with a thermometer was chargedwith 18.1 g of7-amino-3-(benzimidazol-2-yl)thiomethyl-3-cephem-4-carboxylic acid, 300ml of N,N-dimethylformamide and 700 ml of water, and the mixture washeated at 60° C. and stirred. Then, 15.5 g of a1-methyltetrazol-5-ylthio ester of trifluoromethylthioacetic acid wasadded to the mixture, and 20 ml of 0.5N aqueous hydrochloric acid wasfurther added as a reaction catalyst. The mixture was stirred at 60° C.for 2 hours to complete the reaction. When the reaction mixture wasdetermined by high-speed liquid chromatography, it was found that theconversion was 84%. The reaction mixture was cooled and impurities wereremoved from the reaction mixture by extraction with ether according tocustomary procedures. Then, the pH value of the reaction mixture wasreduced to 1.5 by 1N aqueous hydrochloric acid and the reaction productwas extracted with 1 liter of ethyl acetate three times. The extract wasdried over anhydrous magnesium sulfate and the solvent was removed bydistillation under reduced pressure to obtain 15.8 g of7-(trifluoromethylthioacetoamido)-3-(1-methyltetrazol-5-yl)thiomethyl-3-cephem-4-carboxylicacid (Cefazaflur) in the form of a white powder. The product had apurity of 98%.

    ______________________________________                                        Elementary Analysis                                                                             Calculated                                                                              Found                                             ______________________________________                                        C                 33.2%     33.1%                                             N                 17.9%     17.8%                                             F                 12.1%     12.1%                                             S                 20.4%     20.5%                                             H                 2.8%      2.8%                                              ______________________________________                                    

EXAMPLE 27

A 3-liter three-necked flask equipped with a thermometer was chargedwith 27.2 g of 7-aminocephalosporanic acid, 600 ml of acetone and 1400ml of water, and the mixture was heated at 60° C. and stirred. Then,31.0 g of a 1-methyltetrazol-5-ylthio ester of trifluoromethylthioaceticacid was added to the solution, and the resulting mixture was stirred at60° C. for 5 hours to complete the reaction. When the reaction mixturewas determined by high-speed liquid chromatography, it was found thatthe conversion was 58%. The reaction mixture was cooled and impuritieswere removed from the reaction mixture by extraction with etheraccording to customary procedures. The pH value of the reaction mixturewas reduced to 1.5 by 1N aqueous hydrochloric acid, and the reactionproduct was extracted with 2 liters of ethyl acetate three times. Theextract was dried over anhydrous magnesium sulfate and the solvent wasremoved by distillation under reduced pressure to obtain 23.2 g of7-(trifluoromethylthioacetamido)-3-(1-methyltetrazol-5-yl)thiomethyl-3-cephem-4-carboxylicacid in the form of a white powder. The product had a purity of 97%.

EXAMPLE 28

A 3-liter three-necked flask equipped with a thermometer was chargedwith 36.2 g of7-amino-3-(benzimidazol-2-yl)thiomethyl-3-cephem-4-carboxylic acid, 600ml of N,N-dimethylformamide and 1400 ml of water, and the mixture washeated at 60° C. and stirred. Then, 27.5 g of a1-methyltetrazol-5-ylthio ester of cyanomethylthioacetic acid was addedto the mixture, and 40 ml of 0.5N aqueous hydrochloric acid was furtheradded as a reaction catalyst. The mixture was stirred at 60° C. for 1.5hours to complete the reaction. When the reaction mixture was determinedby high-speed liquid chromatography, it was found that the conversionwas 83%. The reaction mixture was cooled, and impurities were removedfrom the reaction mixture by extraction with ether according tocustomary procedures. The pH value of the reaction mixture was reducedto 1.5 by 1N aqueous hydrochloric acid, and the reaction product wasextracted with 2 liters of ethyl acetate three times. The extract wasdried over anhydrous magnesium sulfate and the solvent was removed bydistillation under reduced pressure to obtain 28.6 g of7-(cyanomethylthioacetamido)-3-(1-methyltetrazol-5-yl)thiomethyl-3-cephem-4-carboxylicacid in the form of a white powder. The product had a purity of 97%.

    ______________________________________                                        Elementary Analysis                                                                             Calculated                                                                              Found                                             ______________________________________                                        C                 38.1%     38.1%                                             N                 22.2%     22.1%                                             S                 21.8%     21.9%                                             H                 3.4%      3.3%                                              ______________________________________                                    

EXAMPLE 29

A 300-ml three-necked flask equipped with a thermometer was charged with2.72 g of 7-aminocephalosporanic acid, 60 ml of acetone and 140 ml ofwater, and the mixture was heated at 60° C. and stirred. Then, 2.75 g ofa 1-methyltetrazol-5-ylthio ester of cyanomethylthioacetic acid wasadded to the mixture, and the resulting mixture was stirred at 60° C.for 6 hours to complete the reaction. When the liquid reaction mixturewas determined by high-speed liquid chromatography, it was found thatthe conversion was 52%. The reaction mixture was cooled and impuritieswere removed from the reaction mixture by extraction with etheraccording to customary procedures. Then, the pH value of the reactionmixture was reduced to 1.5 by 1N aqueous hydrochloric acid and thereaction product was extracted with 200 ml of ethyl acetate three times.The extract was dried over anhydrous magnesium sulfate and the solventwas removed by distillation under reduced pressure to obtain 1.83 g of7-(cyanomethylthioacetamido)-3-(1-methyltetrazol-5-yl)thiomethyl-3-cephem-4-carboxylicacid in the form of a white powder. The product had a purity of 98%.

EXAMPLE 30

A 2-liter three-necked flask equipped with a thermometer was chargedwith 18.1 g of7-amino-3-(benzimidazol-2-yl)thiomethyl-3-cephem-4-carboxylic acid, 300ml of N,N-dimethylformamide and 700 ml of water, and the mixture washeated at 60° C. and stirred. Then, 14.4 g of a1-methyltetrazol-5-ylthio ester of 2-thienylacetic acid was added to themixture, and 20 ml of 0.5N aqueous hydrochloric acid was further addedas a reaction catalyst. The mixture was stirred at 60° C. for 2 hours tocomplete the reaction. When the reaction mixture was determined byhigh-speed liquid chromatography, it was found that the conversion was81%. The liquid reaction mixture was cooled and impurities were removedfrom the reaction mixture by extraction with ether according tocustomary procedures. Then, the pH value of the reaction mixture wasreduced to 1.5 by 1N aqueous hydrochloric acid and the reaction productwas extracted with 1 liter of ethyl acetate three times. The extract wasdried over anhydrous magnesium sulfate and the solvent was removed bydistillation under reduced pressure to obtain 13.7 g of7-(2-thienylacetamido)-3-(1-methyltetrazol-5-yl)thiomethyl-3-cephem-4-carboxylicacid in the form of a white powder. The product had a purity of 96%.

    ______________________________________                                        Elementary Analysis                                                                             Calculated                                                                              Found                                             ______________________________________                                        C                 42.5%     42.4%                                             N                 18.6%     18.6%                                             S                 21.2%     21.3%                                             H                 3.5%      3.4%                                              ______________________________________                                    

EXAMPLE 31

A 3-liter three-necked flask equipped with a thermometer was chargedwith 27.2 g of 7-aminocephalosporanic acid, 500 ml of acetone and 1500ml of water, and the mixture was heated at 60° C. and stirred. Then,23.3 g of a 1-methyltetrazol-5-ylthio ester of 2-chloroacetic acid wasadded to the mixture. The resulting mixture was stirred at 60° C. for 6hours to complete the reaction. When the reaction mixture was determinedby high-speed liquid chromatography, it was found that the conversionwas 53%. The reaction mixture was cooled and impurities were removedfrom the reaction mixture by extraction with ether according tocustomary procedures. The pH value of the reaction mixture was reducedto 1.5 by 1N aqueous hydrochloric acid and the reaction product wasextracted with 2 liters of ethyl acetate three times. The extract wasdried over anhydrous magnesium sulfate and the solvent was removed bydistillation under reduced pressure to obtain 15.3 g of7-(2-chloroacetamido)-3-(1-methyltetrazol-5-yl)thiomethyl-3-cephem-4-carboxylicacid in the form of a white powder. The product had a purity of 97%.

EXAMPLE 32

A 2-liter three-necked flask equipped with a thermometer was chargedwith 19.6 g of7-amino-7-methoxy-3-(benzimidazol-2-yl)thiomethylcephalosporanic acid,300 ml of N,N-dimethylformamide and 700 ml of water, and the mixture washeated at 60° C. and stirred. Then, 15.5 g of a1-methyltetrazol-5-ylthio ester of trifluoromethylthioacetic acid wasadded to the mixture and 20 ml of 0.5N aqueous hydrochloric acid wasfurther added as a reaction catalyst. The resulting mixture was stirredat 60° C. for 90 minutes to complete the reaction. When the reactionmixture was determined by high-speed liquid chromatography, it was foundthat the conversion was 93%. The reaction mixture was cooled andimpurities were removed from the reaction mixture by extraction withether according to customary procedures. Then, the pH value of thereaction mixture was adjusted to 1.5 by 1N aqueous hydrochloric acid andthe reaction product was extracted with 1 liter of ethyl acetate threetimes. The extract was washed with water and dried over anhydrousmagnesium sulfate, and the solvent was removed by distillation underreduced pressure to obtain 17.5 g of7-(trifluoromethylacetamido)-7-methoxy-3-(1-methyltetrazol-5-yl)thiomethylcephalosporanicacid in the form of a light yellow powder. The product had a purity of93%.

EXAMPLE 33

A 3-liter three-necked flask equipped with a thermometer was chargedwith 30.2 g of 7-amino-7-methoxycephalosporanic acid, 600 ml of acetoneand 1400 ml of water, and the mixture was heated at 60° C. and stirred.Then, 15 g of a 1-methyltetrazol-5-ylthio ester of 2-chloroacetic acidwas added to the mixture. The resulting mixture was stirred at 50° C.for 6 hours to complete the reaction. When the reaction mixture wasdetermined by high-speed liquid chromatography, it was found that theconversion was 56%. The reaction mixture was cooled and impurities wereremoved from the reaction mixture by extraction with ether according tocustomary procedures. Then, the pH value of the reaction mixture wasadjusted to 1.5 by 1N aqueous hydrochloric acid and the reaction productwas extracted with 2 liters of ethyl acetate three times. The extractwas washed with water and dried over anhydrous magnesium sulfate, andthe solvent was removed by distillation under reduced pressure to obtain17.0 g of7-(2-chloroacetamido)-7-methoxy-3-(1-methyltetrazol-5-yl)thiomethylcephalosporanicacid in the form of a light yellow powder. The product had a purity of95%.

EXAMPLE 34

Substantially the same procedures as in Example 32 were repeated exceptthat 17.2 g of a 1-methyltetrazol-5-ylthio ester ofcyanomethylthioacetic acid was used instead of the1-methyltetrazol-5-ylthio ester of 2-trifluoromethylthioacetic acid, toobtain 16.5 g of7-(cyanomethylthio)acetamido-7-methoxy-3-(1-methyltetrazol-5-yl)thiomethylcephalosporanicacid (Ceftezole) in the form of a light yellow powder. The product had apurity of 93%.

EXAMPLE 35

Substantially the same procedures as in Example 33 were repeated exceptthat 36 g of a 1-methyltetrazol-5-ylthio ester of 2-thienylacetic acidwas used instead of the 1-methyltetrazol-5-ylthio ester of2-chloroacetic acid, to obtain 18.9 g of7-(2-thienyl)acetamido-7-methoxy-3-(1-methyltetrazol-5-yl)thiomethylcephalosporanicacid in the form of a light yellow powder. The product had a purity of88%.

EXAMPLE 36

A 3-liter three-necked flask equipped with a thermometer was chargedwith 27.9 g of 7-amino-7-methoxy-3-chloromethylcephalosporanic acid, 600ml of acetone and 1400 ml of water, and the mixture was heated at 60° C.and stirred. Then, 36 g of a 1-methyltetrazol-5-ylthio ester of2-thienylacetic acid was added to the mixture, and the resulting mixturewas stirred at 50° C. for 6 hours while controlling the pH value at 6.5.After completion of the reaction, the reaction mixture was determined byhigh-speed liquid chromatography. It was found that the conversion was45%. The reaction mixture was cooled and impurities were removed fromthe reaction mixture by extraction with ether according to customaryprocedures. The pH value of the reaction mixture was adjusted to 1.5 by1N aqueous hydrochloric acid, and the reaction product was extractedwith 2 liters of ethyl acetate three times. The extract was washed withwater and dried over anhydrous magnesium sulfate and the solvent wasremoved by distillation under reduced pressure to obtain 20.6 g of7-(2-thienyl)acetamido-7-methoxy-3-(1-methyltetrazol-5-yl)thiomethylcephalosporanicacid in the form of a yellow solid. The product had a purity of 79%.

What is claimed is:
 1. A thioester compound represented by the followinggeneral formula (I): ##STR12## wherein R₁ stands for a p-hydroxyphenylgroup, R₂ stands for an N-carbobenzyloxyamino group and R₃ stands for a1H-1,2,3-triazol-5-ylthio group.